Abstract: The existence form and transformation pattern of phases in Panzhihua titanium concentrate during the oxidation process were studied by thermogravimetry,constant temperature tests,X-ray diffraction analysis and microstructure observations.The results show that the titanium concentrate is not oxidized by oxygen below 500℃.Fe₂Ti₃O₉ and TiO₂ phases start to form when the temperature is 600℃ and the diffraction peak intensities of Fe₂Ti₃O₉,TiO₂ and original phase Fe₂O₃ strengthen with the experimental temperature rising.When the temperature rises at 900℃,Fe₂Ti₃O₉ is substituted by Fe₂TiO₅ and the diffraction peak intensities of TiO₂ and Fe₂O₃ gradually weaken with the experimental temperature rising.Four chemical reactions concomitant with sintering effect occur in the oxidation process;they accelerate the formation of porosities and make the surface of oxidation products rough and loose.